Resources may be accessed by user devices. However, for certain resources, the user devices may need to be assigned an access right in order to be granted access to the resource. A primary load management system may control the assignment of access rights to user devices. Further, for certain resources, access rights may be assigned to user devices on a one-to-one basis. For example, a first access right may be unique among all access rights to a resource. If the first access right is assigned to a first user device, then no other user devices can access the resource using the first access right. In a resource environment under the above-described constraints, characterizing users accessing resources becomes technically challenging as the scale of users grows to big-data levels.